Rechargeable cells, such as the nickel-cadmium cells, have a relatively constant potential during discharge and can be recharged many times, thus extending their useful life. In general, any secondary or rechargeable cell contains a combination of active materials which can be electrolytically oxidized and reduced repeatedly. In rechargeable cells, reactions at both electrodes are reversible and the input of current in the appropriate direction from an outside source will reverse the discharge reaction and, in effect, recharge the electrodes.
The rechargeable cells have been used in various type devices, such as toys, calculators, radios and other types of power-operated devices. Many of the power-operated devices on the market today have been designed to accommodate cylindrical cells of the "AA," "C," and "D" size. These sizes have now become standard-type cells sizes having overall dimensions which can be found in various publications, such as The American National Standard Specifications For Dry Cell Batteries--ANSI C18.1-1969 published by the American National Standards Institute, Inc., New York, N.Y.
There are many different types of chargers on the market which employ standard transformer and half-wave or full-wave rectifier circuit means for providing a direct current for charging rechargeable type cells or batteries. The cell holders of the chargers are generally designed to accommodate a single size cell. Recently, cell holders have been designed which can accommodate two or more standard size cells with or without the use of adapters. Although rechargeable cells generally can be discharged and charged many times, they usually reach a state in which the reactions at both electrodes become non-reversible. The cell at this state is usually referred to as being unable to take or hold a charge. The placement of such cells in battery chargers not only results in a waste of time but also results in a wasteful expenditure of energy from the power source charging the cell.
Rechargeable cells, such as nickel-cadmium cells, off the production line usually have to be initially charged before use. Inadvertently during the manufacture of such cells, some may be improperly assembled or have other defects that render them inoperable as working cells. The charging of these defective cells again would result in a waste of time and a needless expenditure of energy.
One of the objects of the present invention is to provide a rechargeable cell checker that can deliver an initial quick charge and then indicate whether the cell took the charge.
Another object of the present invention is to provide a rechargeable cell checker that can be constructed to accommodate and check various size cells.
Another object of the present invention is to provide a portable rechargeable cell checker having a cell power source for providing a quick charge to a rechargeable cell and a light or meter indicating means to reveal whether the rechargeable cell took and held the charge.
Another object of the present invention is to provide a rechargeable cell checker that has a minimum of parts which are easy to assemble, economical to make and simple to use.
The foregoing and additional objects will become more fully apparent from the following description and the accompanying drawing.